Vegetation plays an important role in the fate of many chemicals. Plants are the first link in terrestrial food chains, and hence the accumulation of chemicals in plants is a crucial step determining exposure of higher terrestrial organisms, including humans, to environmental chemicals. Plants affect the atmospheric transport of chemicals by scavenging them from the air, and they also serve as a medium for transfering chemicals between the soil and the
atmosphere. Plant tissues have potential as biomonitors of air contamination, provided that the partitioning relationship between air and plant concentrations can be quantified. Finally, the accumulation of environmental chemicals in plants can have adverse impacts on the plants themselves.